Robotic platform and method for performing multiple functions in agricultural systems

ABSTRACT

An autonomous vehicle platform system and method configured to perform various in-season management tasks, including selectively applying fertilizer, mapping growth zones and seeding cover crop within an agricultural field, while self-navigating between rows of planted crops and beneath the canopy of the planted crops on the uneven terrain of an agricultural field, allowing for an ideal in-season application of fertilizer to occur once the planted crop is well established and growing rapidly, in an effort to limit the loss of fertilizer.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/188,422 filed Nov. 13, 2018, which is a continuation of U.S.application Ser. No. 15/047,076 filed Feb. 18, 2016, now U.S. Pat. No.10,123,473 issued Nov. 13, 2018, which is a continuation of U.S.application Ser. No. 13/837,786 filed Mar. 15, 2013, now U.S. Pat. No.9,288,938 issued Mar. 22, 2016, which claims the benefit of U.S.Provisional Application Nos. 61/654,444 filed Jun. 1, 2012, 61/723,887filed Nov. 8, 2012 and 61/739,268 filed Dec. 19, 2012, entitled RoboticPlatform and Method for Performing Multiple Functions in AgriculturalSystems, each of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to methods and robotic platformsfor use in agriculture. More particularly, the present invention relatesto an autonomous vehicle platform configured to perform variousin-season management tasks between the planted rows of an agriculturalfield, including nitrogen fertilization, and methods for accomplishingthe tasks.

BACKGROUND OF THE INVENTION

After a growing plant exhausts the nutrient resources stored in itsseed, it begins to drawn in nutrients from the surrounding soil usingits root system. Rapidly growing plants have a high need for nutrients.If a plant cannot access the necessary nutrients then its growth becomeslimited. Such nutrient limitation can impact the overall growth of theplant, the production of seeds, such as corn kernels, and the economicreturn to the farmer. Corn plants, in particular, require nitrogen atleast until reaching the point when tassels appear, which may be atheights of 2 m (6 feet), or more. Farmers use a range of strategies forincreasing the availability of nutrients for a growing crop, mostnotably the addition of chemical fertilizers, for example nitrogen andphosphorus.

Generally, externally-added nitrogen has the potential to be lost fromfarm fields more readily than does externally-added phosphorus. Nitrate,a commonly found form of nitrogen that is negatively charged, dissolvesreadily in water and is lost as water runs off fields into drainageditches or streams, or as water seeps downward into groundwater.Agricultural runoff containing significant concentrations of chemicalfertilizers, such as nitrogen, can lead to degraded water quality indownstream water bodies. In addition, elevated levels of nitrate ingroundwater can be a human health threat.

Ammonium is a positively charged ion that generally will bind to soilparticles and will, therefore, be resistant to loss via runoff. However,in alkaline conditions, ammonium transforms into its gaseous form,ammonia, which can be readily lost to the atmosphere. Furthermore,ammonium can be transformed into nitrate—and subsequently lost from thefield—via a microbial process known as nitrification.

Fertilizer containing urea is susceptible to significant loss whenapplied to the soil surface. Specifically, the urea is hydrolyzed, orbroken down, releasing ammonia gas. However, if this happens within thesoil profile, there is less chance the ammonia gas will be lost to theatmosphere; with favorable soil chemistry, ammonia is converted toammonium, a more stable form of nitrogen. Fertilizer additives arecurrently marketed to reduce temporarily the rate of urea hydrolysis.

Nitrogen can also be lost through a process known as denitrification,whereby nitrate is converted to gaseous forms of nitrogen, includingdinitrogen—the form of nitrogen found in the atmosphere—and nitrousoxide. Nitrous oxide carries with it several serious environmentalconcerns; namely, it is a greenhouse gas many times more potent thancarbon dioxide, it contributes to stratospheric ozone depletion, and itcontributes to smog.

Nitrogen can also be lost from the soil through microbial-mediatedprocesses that create other gaseous forms of nitrogen. Warmer soiltemperatures cause microbial processes to occur more rapidly, meaningthat nitrogen fertilizer remaining in or on warmer soils is increasinglysusceptible to this type of loss.

Phosphorus is most commonly found in soils as phosphate. By contrast tonitrogen, phosphorus readily binds to soil particles. Nevertheless,phosphorus can be lost from fields through soil erosion or, lesscommonly, via runoff if the soil can no longer bind additional phosphatebecause all available binding sites are filled.

Fertilizer costs, which are closely tied with the cost of fossil fuels,are significant in the production of commodity crops like corn.Fertilizer that is lost from the farm field represents inefficiency inagricultural production systems, as well as a potential loss in profitrealized by the farmer. Particularly in the case of nitrogen fertilizer,the longer an externally-applied fertilizer remains on an agriculturalfield, the more opportunities there are for the fertilizer to be lost asdescribed above.

Pre-season applications of fertilizer is common, either in the late fallfollowing harvest or around the time of planting in the spring. Bothfall and spring applied nitrogen has the potential of being lost fromthe field during heavy spring rains, plus fall applied nitrogen hasseveral additional months on the field when it can be lost due to thevarious processes outlined above.

As a crop becomes established, it effectively pumps water from the soilto the atmosphere through a process known as transpiration. As a crop'sleaf area increases, its ability to pump water from soil to atmosphereincreases. In part, because of a crop's increased ability to pump watervia transpiration, there is a reduced chance that heavier rains willlead to runoff. Nevertheless, heavy rains that lead to flooding stillincrease the likelihood of nitrogen loss via denitrification, especiallyif soils are warmer.

The substantial cost of fertilizer in the production of commodity cropslike corn incentivizes farmers to adjust applications to match the needsof what their crop will ultimately require throughout the growingseason. Yet, farmers are prone to over-apply nitrogen out of anxietythat there will be insufficient nitrogen available when it is requiredby their growing crop. Furthermore, some farmers forego in seasonapplication of nitrogen because of their anxiety about being able to getthe necessary equipment on the field within the appropriate time window.

Additionally, farmers contend with a range of tradeoffs when consideringthe timing and size of fertilizer applications. For example, fertilizeris often cheaper in the fall, although there is increased likelihood ofnitrogen losses with fall application.

Farm fields are heterogeneous, with one location potentially varyingyear-to-year in its nutrient status and differing from locations in itsimmediate vicinity. It is standard for farmers to assess soil nutrientstatus with periodic samples analyzed in a laboratory. Soil tests areused to estimate nutrient needs prior to the growing season, in season,or prior to an in season application of nitrogen. Independent cropconsultants are commonly retained by farmers to help interpret labanalyses of soil tests and management practices. Similarly, land grantuniversities have extension agronomists who are able to assist farmersin these types of management decisions.

The potential for heterogeneity of nutrient status across a given fieldhas led some to develop a soil sampling system that blends together alarge number of samples taken as the equipment travels across a field.This approach may, however, mask finer-scale heterogeneity that could beused to guide variable applications of fertilizer across a field.

In recent years, instruments that measure optical properties of thegrowing plants are being used to indicate zones of nutrient deficiencythat can subsequently be addressed with the precision application offertilizer containing the necessary nutrient. In some cases, theseinstruments are used at the same time a farmer is fertilizing a field,with near-instantaneous adjustments made to meter the appliedfertilizer. Strategies have been developed for mapping field zones toaid in the application of fertilizer.

The use of tractor-drawn and self-propelled equipment to manage rowcrops is well known. In situations where taller crops requiremanagement, the use of tractor-drawn equipment is possible to a point,beyond which, high-clearance vehicles are required. In situations wherehigh clearance is required, it is possible to use airplanes to applyagricultural chemicals and even to seed cover crops, although airplaneapplication is not feasible or ideal in many situations.

Corn plants, in particular, require nitrogen at least until reaching thepoint when tassels appear, which may be at heights of six feet or more.Conventional tractor-drawn implements are incapable of applyingfertilizer when corn is so tall, which has led to the use ofself-propelled sprayer systems, often referred to as “high boy” systems.Such high-boy systems are capable of straddling corn that is about sixfeet tall.

A typical nitrogen fertilizer used in such applications is known as UAN(liquid mixture of urea and ammonium nitrate in water). Best practicesinclude working fertilizer such as UAN into the soil between rows ofcorn rather than spraying it on the soil surface. Justifications includeresearch that indicates there will be less loss of nitrogen throughvolatilization and absorption by decaying plant material on the soilsurface which tends to bind the UAN, inhibiting the movement of UANdownward through the soil toward the crop's roots.

The leaves of growing corn plants, in particular, can develop visiblecolor changes if contacted by concentrated nitrogen fertilizer, such asUAN. While research suggests that there is no long term impact on cornyields, such apparent crop damage is viewed negatively by many farmers.A modification that helps to alleviate this concern with high-boysprayers is to attach tubes to the sprayer nozzles that extend to thesoil surface. Nevertheless, these dangling tubes, attached to afast-moving vehicle, can still result in concentrated nitrogenfertilizer splashing on the corn leaves.

Because of the concern that valuable fertilizer can be lost to theatmosphere through denitrification, further modifications of high-boysystems include implements that drop down from an elevated toolbar andwork the liquid fertilizer into the soil surface with a disc or coulter.High-boy systems can be used to apply nitrogen in this manner when cornplants are tall, but these systems are currently limited to corn that isabout six feet tall. Furthermore, except in the case of when a coultersystem is used, such equipment is not designed to apply UANdirectionally at base of the plants, especially for taller corn. Rather,UAN is sprayed or integrated more or less indiscriminately between rows.However, in an effort to avoid splashing UAN directly on to the cornplants themselves, there are after-market products designed to guide theliquid stream to the ground.

Cover crops, which are generally seeded between the time that cash cropsare grown, can provide a number of benefits in agriculture. A field witha cover crop may have less soil erosion. Some cover crops, which fixnitrogen from the atmosphere, can augment the amount of soil nitrogen ina field and reduce the need for applied fertilizer. As cover crops grow,they take up and store nutrients, essentially preventing them from beinglost from the field in runoff or in other ways. In addition, some covercrops with deep roots can substantially reduce soil compaction.

In a crop like corn, an ideal time to seed a cover crop is when theplants are tall and their leaves are beginning to senesce (i.e., turnbrown), thereby allowing sufficient light for cover crop growth topenetrate the leaf canopy. At these times, cover crops havetraditionally been seeded by airplane or in some situations bycustomized high-clearance systems.

More recently, there has been an interest in the use of small roboticvehicles on farms. The notion of a tractor that could navigateautonomously first appeared in patent literature in the 1980s. Forexample, U.S. Pat. No. 4,482,960, entitled “Robotic Tractors,” disclosesa microcomputer based method and apparatus for automatically guidingtractors and other farm machinery for the purpose of automatic cropplanting, tending and harvesting.

In 2006, one study concluded that the relatively high cost of navigationsystems and the relatively small payloads possible with small autonomousvehicles would make it extremely difficult to be cost effective withmore conventional agricultural methods. Accordingly, many of theautonomous vehicles that have been developed are relatively large insize. For example, the Autonomous Tractor Corporation has touted thedevelopment of the SPIRIT autonomous tractor, which is a 102 inch wide“driverless,” tracked vehicle, theoretically capable of tilling,harvesting and hauling. The SPIRIT tractor, scheduled to be on themarket in 2013, will use Laser Induced Plasma Spectroscopy (LIPS) tonavigate on the field—a local system (not requiring satellites) thatmust be trained so that it can “learn” the layout of a particular field.The SPIRIT tractor will use RADAR to avoid unexpected obstacles, likehumans or other animals.

Another example is the BONIROB vehicle, which is a 1.2 m (4 ft) widefour-wheeled robotic vehicle marketed by the German company Amazone. Yetanother example is U.S. Pat. No. 7,765,780, entitled “Agricultural RobotSystem and Method,” which discloses an agricultural robot system with arobotic arm for use in harvesting of agricultural crops. However, noneof these robot systems or vehicles is sufficiently narrow to allow fortravel between typical planted rows in an agricultural field.

Despite the difficulty in maintaining cost effectiveness, a limitednumber of smaller agricultural robots have also been developed. Forexample, the Maruyama Mfg. Co has developed a small autonomous vehiclefor spraying greenhouse crops. This machine is capable of navigatingbetween rows of crops; however it is limited to operating in theconstrained situations of a greenhouse. Moreover, it is not suited forthe uneven terrain typical of an agricultural field.

Another example is U.S. Pat. No. 4,612,996, entitled “RoboticAgricultural System with Tractor Supported on Tracks,” discloses atractor which traverses between planted rows on a track system. However,use of this system first requires the installation of an elaborate andpotentially expensive track system within the agricultural field.Moreover, it is unclear how such a small tractor can provide coverage toa large agricultural field, much less multiple large agriculturalfields, within a reasonable window of time.

Accordingly, what is needed in the industry is a device which canautonomously navigate between the planted rows and beneath the canopy ofmature plants on the uneven terrain of an agricultural field toaccomplish in-season management tasks, such as selectively applyingfertilizer, thereby enabling the application of fertilizer throughoutthe life of the crop to minimize fertilizer loss in an effort tomaximize the profit realized by the farmer. Moreover, what is needed bythe industry is a system in which several small autonomous devices canwork cooperatively together, in an efficient manner, to completein-season management tasks within multiple large agricultural fields ina reasonable window of time, for example over the course of a day orseveral days to ensure that fertilizer is applied to crops atsubstantially the same point in their growth cycle.

SUMMARY OF THE INVENTION

The present invention provides embodiments of an autonomous vehicleplatform system and method configured to perform various in-seasonmanagement tasks, including selectively applying fertilizer to the soilof an agricultural field, while self-navigating between rows of plantedcrops and beneath the canopy of planted crops on the uneven terrain ofan agricultural field. Accordingly, the present invention enables, forinstance, the ideal in-season application of fertilizer to occur once aplanted crop is well established and growing rapidly. Timely applicationof fertilizer limits fertilizer loss, since established planted crops,as compared to seedlings, can more rapidly take up water and fertilizerfrom the soil. The present invention can also be employed when theplanted crop height is low in order to automate some functions, such asfertilizing (i.e., when outside of the in-season timeframe).

An autonomous vehicle platform system is comprised of one or moreautonomous vehicle platforms. Each autonomous vehicle platform includesa base operably connected to a plurality of ground contacting wheels.Each autonomous vehicle platform has a length, width and height, whereinthe width is so dimensioned as to be insertable through the spacebetween rows of planted crops (i.e., the gap between rows), wherein theheight is so dimensioned as to preclude interference with the canopy ofthe planted crops. Each autonomous vehicle platform is programmed with aself direction program to autonomously navigate, and to avoid otherautonomous vehicle platforms, while selectively performing an in seasonmanagement task, such applying fertilizer within an agricultural field.

The autonomous vehicle platform system can also have one or morerefilling stations. When one or more refilling stations are present,each autonomous vehicle platform can be programmed to compare the statusof autonomous vehicle platform criteria to a programmed threshold, andto navigate to the refilling station for servicing based on saidcomparison.

Each autonomous vehicle platform can also include a user interfaceconfigured to transmit data to a user of the autonomous vehicleplatform, and be further configured to receive command data from theuser of the autonomous vehicle platform for selectively overriding theself-direction program from a remote location.

A method for fertilizing between a series of planted rows within anagricultural field with one or more autonomous vehicle platformsincludes delivering one or more autonomous vehicle platforms to anagricultural field, positioning a refilling station proximate theagricultural field, orienting the one or more autonomous vehicleplatforms to the agricultural field and the refilling station, andactivating the self-direction program of each autonomous vehicleplatform. Besides each autonomous vehicle platform being programmed witha self-direction program to autonomously navigate the autonomous vehicleplatform and to avoid other autonomous vehicle platforms whileaccomplishing crop management tasks, such as selectively applyingfertilizer.

The above summary of the invention is not intended to describe eachillustrated embodiment or every implementation of the present invention.The figures and the detailed description that follow more particularlyexemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more completely understood in consideration of thefollowing detailed description of various embodiments of the invention,in connection with the accompanying drawings, in which:

FIG. 1A is a rear view of an autonomous vehicle platform in accordancewith an example embodiment of the invention;

FIG. 1B is a side view of an autonomous vehicle platform in accordancewith an example embodiment of the invention;

FIG. 2 is a schematic of the autonomous vehicle platform in accordancewith an example embodiment of the invention;

FIG. 3 is a top view of an agricultural field wherein autonomous vehicleplatforms are autonomously navigating between rows of planted crops withperiodic return to a refilling station for servicing or resupply inaccordance with an example embodiment of the invention;

FIG. 4A is a top view of an agricultural field wherein autonomousvehicle platforms have spiked drums for making penetrations into thesoil in accordance with an example embodiment of the invention;

FIG. 4B is a perspective view of a spiked drum in accordance with anexample embodiment of the invention;

FIG. 5A is a top view of an autonomous vehicle platform with mechanicalfeeler arms traveling between two rows of planted crops in accordancewith an example embodiment of the invention;

FIG. 5B is similar to FIG. 5A, but with an autonomous vehicle platformbeing closer to one row of planted crops than the other row of plantedcrops in accordance with an example embodiment of the invention;

FIG. 6 is a top view of an autonomous vehicle platform with mechanicalfeeler arms traveling between two rows of planted crops, wherein themechanical feeler arms can detect individual crop plants within a row ofplanted crops in accordance with an example embodiment of the invention;

FIG. 7 is a side view of an autonomous vehicle platform with afertilization tank and fertilization module for selective application offertilizer within an agricultural field in accordance with an exampleembodiment of the invention;

FIG. 8A is a rear view of an autonomous vehicle platform with a tankpositioned above the wheels in accordance with an example embodiment ofthe invention;

FIG. 8B is a side view of an autonomous vehicle platform with a tankpositioned above the wheels in accordance with an example embodiment ofthe invention;

FIG. 9A is a rear view of an autonomous vehicle platform with a tankincorporated into the wheels in accordance with an example embodiment ofthe invention;

FIG. 9B is a side view of an autonomous vehicle platform with a tankincorporated into the wheels in accordance with an example embodiment ofthe invention;

FIG. 10 is a top view of an autonomous vehicle platform applyingfertilizer substantially between two rows of planted crops in accordancewith an example embodiment of the invention, with the autonomous vehicleplatform depicted in a first and second direction;

FIG. 11 is a top view of an autonomous vehicle platform applyingfertilizer to the base of planted crops in accordance with an exampleembodiment of the invention, with the autonomous vehicle platformdepicted in a first and second direction;

FIG. 12A is a rear view of an autonomous vehicle platform wheel withfertilization module incorporated into the wheel in accordance with anexample embodiment of the invention;

FIG. 12B is a side view of an autonomous vehicle platform wheel with afertilization module incorporated into the wheel, with the wheeldepicted in various stages of rotation in accordance with an exampleembodiment of the invention.

FIG. 13 is a side view of an autonomous vehicle platform with a roboticarm having a sensor and soil moisture probes for mapping plant growthzones within an agricultural field in accordance with an exampleembodiment of the invention;

FIG. 14 is a side view of an autonomous vehicle platform with a seedreservoir and a seeding module for planting cover crops in anagricultural field in accordance with an example embodiment of theinvention;

FIG. 15 is a side view of autonomous vehicle platform refilling at arefilling station in accordance with an example embodiment of theinvention;

While the invention is amenable to various modifications and alternativeforms, specifics thereof have by shown by way of example in the drawingsand will be described in detail. It should be understood, however, thatthe intention is not to limit the invention to the particularembodiments described. On the contrary, the intention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIGS. 1-3, an autonomous vehicle platform 100 operates inan agricultural field 102, primarily in situations where human-operatedequipment cannot easily be operated. The autonomous vehicle platform 100is, like a typical farm tractor, capable of accepting a number ofimplements configured to perform various in-season management tasks.However, unlike a typical farm tractor, the autonomous vehicle platform100 is capable of autonomous navigation between rows of planted crops104 and for taller crops, below the canopy formed by the leaves of theplanted crops 104 (i.e., beneath the canopy of planted crops 104).

At least three main implements of the autonomous vehicle platform 100configured to perform various in-season management tasks include: asystem for applying fertilizer (as depicted in FIG. 7), a system formapping plant growth zones within an agricultural field 102, includingthe nutrient status of plants (as depicted in FIG. 13), and a system forseeding a cover crop (as depicted in FIG. 14). There are also a varietyof management task applications for the autonomous vehicle platform 100.For example, a user can employ the autonomous vehicle platform 100 evenwhen planted crop 104 height is low in order to automate some functions,such as fertilizing (i.e., when outside of the in-season timeframe).

The autonomous vehicle platform 100 has a vehicle base 106 with a lengthL, width W and height H. The width W of the vehicle base 106 is sodimensioned as to be insertable through the space between two rows ofplanted crops 108. In one embodiment, width W of vehicle base 106 can bedimensioned to be less than about 30 inches wide and can be used inconjunction with rows of planted crops 108 36 inches wide (i.e., crops104 planted on 36 inch centers). In another embodiment, width W ofvehicle base 106 can be dimensioned to be less than about 20 inches wideand can be used in conjunction with rows of planted crops 108 30 incheswide. The height H of the vehicle base 106 is so dimensioned as topreclude interference with the canopy of the planted crops 104. Thus,the autonomous vehicle platform 100 is capable of traveling between rowsof tall planted crops 108, such as corn or sunflowers, without beinglimited by the height of the planted crops 104.

The autonomous vehicle platform 100 has a plurality of ground contactingwheels 110, tracks, or some combination thereof to move acrossagricultural field 102. Given the combination of relatively unevensurfaces and potentially soft ground conditions the wheel size andground contact should be maximized. Wheeled versions could have three ormore wheels 110. A tracked version could have multiple tracks, possiblyin combination with one or more wheels 110 to aid in steering. Asdepicted in FIGS. 4A and 4B, one embodiment can include spiked drums 112to serve as a mechanism for making penetrations into the soil 114. Thespiked drums 112 can also serve effectively as the autonomous vehicleplatform wheels 110.

The autonomous vehicle platform 100 can operate effectively across arange of surface conditions created by different cultivation methods(e.g., no-till, low-till, strip-till, and conventional tillage), and ondifferent soil 114 types with different crops 104 planted the previousyear (i.e., over a range of plant residue conditions). In addition, theautonomous vehicle platform 100 can operate on soils 114 that would betoo wet for conventional equipment.

The autonomous vehicle platform 100 has at least one powertrain fixedlycoupled to vehicle base 106 and operably coupled to at least one of theplurality of wheels 110. In one embodiment a battery can be the mainpower source for powertrain 116. In another embodiment, a small internalcombustion engine, fueled by diesel or gasoline, can be the main powersource for powertrain 116. In yet another embodiment, a conventionalengine can be paired with a battery to create a hybrid power system; inthis configuration, the batteries can power an electrical powertrain 116and the engine can charge the batteries. In one embodiment, the mainpower source for the powertrain 116 can operate continuously for morethan 20 hours per day.

The autonomous vehicle platform 100 has a navigation module 118configured to receive field orientation information and detect obstaclesusing a variety of inputs, including existing data about a particularagricultural field 102, as well as navigational data acquired in realtime, such as data acquired via onboard cameras, radio communicationwith a base station, and global positioning system GPS units. A mast 120can be in communication with the navigation module 118 to allow for anextended range and improved reception beneath the canopy of the plantedcrops 104.

As shown in FIG. 5A, the autonomous vehicle platform 100 can havemechanical “feelers” 122A and 122B to gauge its location relative torows of planted crops 108. As the autonomous vehicle platform 100 movescloser to a given row of planted crops 108, the feeler 122A on that sideof the autonomous vehicle platform 100 folds inward and the feeler 122Bon the other side of the autonomous vehicle platform 100 extendsoutward—this can be seen by contrasting FIGS. 5A and 5B, andspecifically the change in angle “a” to a more acute angle “c” and angle“b” to less acute angle “d.”

This mechanical feeler system requires a real-time algorithm fordetermining the change in feeler angles, for adjusting autonomousvehicle platform 100 steering to maintain a preferred set of feelerangles. This mechanical feeler system functions particularly well inagricultural fields 102 that have been planted using the high-accuracyRTK-GPS, because rows of the planted crops 104 are typically verystraight and there would be relatively less fluctuation of feelerangles.

This mechanical feeler system also allows the autonomous vehicleplatform 100 to know with a high degree of accuracy the location ofindividual planted crops 104 within a row of planted crops 108. As shownin FIG. 6, for planted crops 104 with rigid stalks, such as corn, theautonomous vehicle platform 100 can have shortened feelers 124A and 124Bthat flip in and out as they pass each plant. Such feelers 124A and 124Bcan be used simply to count plants or to modulate the application offertilizer. For example, the feelers 124A and 124B can be used toidentify the location of individual planted crops 104 along a row ofplanted crops 126 for application of fertilizer to that specific plantedcrop 104.

The autonomous vehicle platform 100 can have a microprocessor 126 incommunication with the navigation module and other implements,programmed with a self-direction program to autonomously navigate theautonomous vehicle platform, and to avoid other autonomous vehicleplatforms 100, while selectively utilizing one of three main implements,(e.g., fertilization, mapping plant growth zones, or seeding cover crop)based in part on received field orientation information and detectedobstacles. For example, an agricultural field 102 can contain variousrocks, debris, and other objects that might obstruct the movement ofautonomous vehicle platform 100. Small animals, including pets, as wellas humans young and old, can also be encountered by the autonomousvehicle platform 100. The autonomous vehicle platform 100 can haveonboard capabilities to detect, avoid, navigate around, or navigate overa range of obstacles like these. Additionally, when more than oneautonomous vehicle platform 100 is autonomously navigating in anagricultural field, the autonomous vehicle platform 100 can communicatewith other autonomous vehicle platforms 100 in order to coordinateactivities and avoid collisions.

The autonomous vehicle platform 100 can have a user interface module 128in communication with microprocessor 126, configured to transmitmicroprocessor data to a user of the autonomous vehicle platform 100,and further configured to receive command data from the user of theautonomous vehicle platform for selectively overriding theself-direction program. For example, in one embodiment, a user canreceive video and other sensor data remotely via wirelesscommunications, and send control signals to selectively overrideautonomous vehicle platform 100 automation. Accordingly, a user can havea range of possibilities for interacting with the autonomous vehicleplatform 100. The user can interact in real time via an application on amobile device, such as a smartphone or tablet, which communicatesdirectl, or indirectly via a server, with the autonomous vehicleplatform 100. The user can interact in real time via a user interfaceonboard the autonomous vehicle platform 100. And, the user can alsoperiodically interact with, and monitor, the autonomous vehicleplatforms 100 via web-based or pc-based software some distance from theagricultural field 102, such as from a farm headquarters.

A. Fertilization

As shown in FIG. 7, the autonomous vehicle platform 100 can support afertilization tank 130 and fertilization module 132 configured forselective application of fertilizer to the soil 114 of an agriculturalfield 102 or base of planted crops 104. The fertilization module 132 canbe in communication with microprocessor 126. The fertilization module132 can be positioned in front, underneath, or behind the wheels 110 (ortracks), or on the wheels 110 of the autonomous vehicle platform 100.

The autonomous vehicle platform 100 can utilize a liquid fertilizerknown as UAN (urea-ammonium-nitrate), other liquid, dry, or granularfertilizers. In one embodiment, the fertilizer tank 130 can hold lessthan 20 gallons of UAN. In another embodiment, the fertilizer tank 130can hold less than 40 gallons of UAN. In another embodiment, thefertilizer tank 130 can hold less than 50 gallons of UAN. Thefertilization tank 130 can be pressurized by compressed air, which couldbe supplied from a central compressor to aid in the delivery offertilizer. Alternatively, the fertilizer can be pumped from thefertilization tank 130 into the fertilization module 132. Automatedvalves and pumps can further be used to inject the fertilizer solutioninto the soil 114. Baffles can be added to limit sloshing of liquidfertilizer.

As shown in FIGS. 8A and 8B, in one embodiment, the fertilizer tank 130can be positioned above the wheels 110. In other embodiments, thefertilizer tank 130 can be slung even with, or below the center of thewheels 110.

As shown in FIGS. 9A and 9B, in another embodiment, the fertilizer tank130 can be incorporated into the wheels 110 of the autonomous vehicleplatform 100. Incorporating the tank 130 into the wheels 110 providesthe lowest-possible center of gravity—even lower than a low-slung tank.With this embodiment, liquid fertilizer can be pumped, or otherwiseallowed to flow, from one side of the autonomous vehicle platform 100 tothe other. Thus, if it is known that the autonomous vehicle platform 100will soon encounter a side slope, to improve stability, fluid can betransferred to the tank 111 that will be at a higher elevation.

In yet another embodiment, the fertilizer tank 130 can be a wagon pulledby the autonomous vehicle platform 100. With this embodiment thefertilization module 132 can be positioned on the autonomous vehicleplatform base 104 or on the wagon. The autonomous vehicle platform 100can also incorporate combinations of the described fertilizer tank 130configurations.

Depending on a range of variables, including soil type, soil moisture,and plant residue, various approaches can be used for applyingfertilizer. In some embodiments, the fertilization module 132 caninclude a spray nozzle 133 to spray fertilizer on the soil 114 surface.As shown in FIG. 10, the fertilizer can be applied substantially betweentwo rows of planted crops 108; in this manner the autonomous vehicleplatform 100 effectively treats one half of each row of planted crop104. For example, the autonomous vehicle platform 100 can utilize acircular disc, or coulter 134, that cut slots into the soil 114 as theyare moved across the soil 114 surface. The fertilizer solution can besprayed into this slot directly behind the coulter 134. Alternatively, aprotective metal “knife” can be used directly behind the coulter 134,with a tube passing down behind the knife to introduce the fertilizersolution into the soil. Given the light weight of the autonomous vehicleplatform 100, it may be necessary to add weights to the vehicle topermit sufficient downward pressure to operate the coulter 134.

As depicted in FIG. 4, multi-pronged wheels or spiked drums 112—likethose that are used on agricultural cultivators to aerate soil can beincorporated. Fertilizer can be injected either through the middle ofthese prongs or spikes 136 while in contact with the soil 114, orsubsequent to ground contact by the fertilization module 132 in the holeleft after the spiked drum 134 has passed over the soil 114.

In yet other embodiments, the autonomous vehicle platform 100 can applythe fertilizer in a combination of locations, including one or morelocations besides substantially between two rows of planted crops 104.As depicted in FIG. 11, the autonomous vehicle platform 100 can applyfertilizer proximate to the base of planted crops 104. In this mannerthe autonomous vehicle platform 100 effectively treats two rows ofplanted crop 108 on each pass, thereby doubling its coverage incomparison to fertilization substantially between two rows of plantedcrops 108. Note that when a UAN solution is sprayed proximate to thebase of planted crops 104, a stabilizer can be added to preventhydrolysis of the urea to ammonia gas lost to the atmosphere throughvolatilization. However, rain or application of irrigation waterfollowing fertilizer application can eliminate the need to treat the UANwith a stabilizer. A focused spray to specifically avoid application tocrop residue can eliminate the amount of fertilizer inadvertentlyimmobilized.

In addition to application of fertilizer as a spray proximate to thebase of planted crops 104, the autonomous vehicle platform 100 canfollow the fertilizer application with a spray of water, as “simulatedrain.” Thus, the autonomous vehicle platform 100 can have two tanks, onefor fertilizer 130 and one for water. The simulated rain applicationhelps to wash the UAN fertilizer into the soil, thereby reducinghydrolysis on the soil 114 surface.

As shown in FIGS. 12A and 12B, in one embodiment, the fertilizationmodule 112 can be a spray nozzle 138 incorporated into the sidewall ofone or more wheels 110. In this embodiment, the spray nozzle 138 can bemomentarily pulsed on at the top arc of the wheel 110 motion. The streamproduced from the spray nozzle 138 can be focused on a single spot onthe soil 114 or proximate to the base of a planted crop 104 for aspecified duration of time, thereby allowing direct, concentratedapplication of fertilizer.

In another embodiment, the autonomous vehicle platform 100 can apply dryfertilizer pellets in a precise manner directly proximate to the base ofa planted crop 104 or substantially between rows of planted crops 108,by injecting the pellets several inches into the soil in a manner thatdoes not damage the crop's root system. In one embodiment, a rolling,spiked drum 112 is used for this purpose. In another embodiment, theautonomous vehicle platform 100 “shoots” pellets into the ground using ahigh-pressure air system much like what is found in air rifles thatfires a BB or a pellet. Fertilizer can be applied on either side ofautonomous vehicle platform 100.

The autonomous vehicle platform 100 can monitor the fertilization. Forexample, detailed monitoring of the flow of nutrients into the soil 114can be provided to the user during fertilizing operations. In anotherexample, the autonomous vehicle platform 100 can detect and rectify asituation where soil 114 becomes stuck to the coulter 134 or other partsof the equipment. The autonomous vehicle platform 100 can be equipped tomonitor the depth at which it is injecting fertilizer.

In addition to fertilization, a range of herbicides, pesticides, andfungicides can be applied to planted crops 104, such as corn. In someembodiments, autonomous vehicle platform 100 can detect which plantsneeds a particular fungicide and then apply that fungicide using asprayer on a mast 120 or a robotic arm 140. Such an approach would havethe potential of reducing the volume of chemicals applied while stillmaintaining—or even increasing—crop yields.

Autonomous operation of the autonomous vehicle platform 100 can bemanaged and selectively overridden by one or more pc- or web-basedsoftware programs that a user can access via smartphone, tablet,interface on base station, or personal computer at the farmheadquarters.

B. Mapping Plant Growth Zones

The autonomous vehicle platform 100 can have the capability to map plantcondition as well as other parameters, such as soil moisture. Generally,such equipment can be in the form of an attachment connected to thevehicle base 106, integrated with the autonomous vehicle platform 100,or it could be in the form of a dedicated mapping autonomous vehicleplatform 100. One goal of the mapping system is to guide the applicationof fertilizer. Thus, in areas where plant conditions indicate that lessnutrients are required, the autonomous vehicle platform 100 will applyless fertilizer.

As shown in FIG. 13, the autonomous vehicle platform 100 can have asensor 142 for monitoring plants, optionally mounted on a robotic arm140. The purpose of sensor 142 is to characterize plant conditions.Sensor 142 is in communication with the microprocessor 126. Such asensor 142 can use optical or other measurements to determine theabundance of plant pigments, such as chlorophyll, or other keyparameters. Although sensor 142 can measure properties optically frombelow planted crops 104, it is advantageous to attach sensor 142 torobotic arm 140 to access plant material above the autonomous vehicleplatform 100.

The autonomous vehicle platform 100 can have one or more soil moistureprobes 144 to help map plant growth zones. Soil moisture probe 144 is incommunication with the microprocessor 126. Operationally, the autonomousvehicle platform 100 can stop periodically and insert its soil moistureprobe 144 into the soil 114, potentially while it is taking opticalreadings from several nearby planted crops 104.

The autonomous vehicle platform 100 can be programmed with an algorithmto improve efficiency in real-time plant monitoring. For example, if theautonomous vehicle platform 100 is programmed to stop periodically totake measurements, the algorithm can analyze these measurements todetermine how much they vary from one another. Where adjacentmeasurements do not vary substantially, the algorithm can enable theautonomous vehicle platform 100 to increase the distance betweenmonitoring locations, thereby effectively speeding up the monitoringprocess.

In addition to data collected via sensor 142 and soil moisture probe144, data from crop planting operations can be used create a “base map”from which the autonomous vehicle platform 100 can navigate. Such a basemap can detail the precise location of individual rows of planted crop108, or even the location of individual plants 104. The base map canalso describe the soil 114 types and field topography—includingmeasurements made using LIDAR that describe drainage patterns on afield. A user can further interact with the map, via an interface,adding in expert knowledge. For example, the existence of different cropvarieties or typically-wet areas can be added by the user.

Use of the autonomous vehicle platform 100 can also be guided byexternal inputs, such as weather data. For example, the user's decisionon whether to fertilize at a given point in time can be influenced byinputs like weather data that ultimately predict the effectiveness ofapplying fertilizer within a given time window. Thus, the user can optto delay fertilizing operations if a predicted rain storm is likely towash a substantial portion of the added fertilizer off the field.

Like the other embodiments, autonomous operation of the autonomousvehicle platform 100 can be managed and selectively overridden by one ormore pc- or web-based software programs that a user can access viasmartphone, tablet, interface on base station, or personal computer atthe farm headquarters.

C. Seeding Cover Crop

Another embodiment of the autonomous vehicle platform 100 can be usedfor seeding cover crops under tall planted crops 104, like corn. Asshown in FIG. 14, the autonomous vehicle platform 100 can have a seedreservoir 146 containing seeds coupled to the vehicle base 106. Theseeds can be mixed in a water solution. Seeds can be applied to the soil114 surface via a seeding attachment 148, and can be worked into thesoil using a range of common tillage methods, such as dragging a metalbar or chain. Seeding attachment 148 is coupled to microprocessor 126.Seeding cover crops can be performed while fertilizing, or during anindependent (non-fertilization) pass through the agricultural field 102.Thus, the autonomous vehicle platform 100 can have a seed reservoir 146and seeding attachment 148 in combination with fertilization and mappingequipment.

Like the other embodiments, autonomous operation of the autonomousvehicle platform 100 can be managed and selectively overridden by one ormore pc- or web-based software programs that a user can access viasmartphone, tablet, interface on base station, or personal computer atthe farm headquarters.

D. Refilling Station

As shown in FIG. 15, each autonomous vehicle platform 100 can beprogrammed to periodically return to a refilling station 150. Therefilling station 128 can include a refilling tank 152 and a refillingapplicator 154. When used in conjunction with a refilling station 150,each autonomous vehicle platform 100 is programmed to compare the statusof autonomous vehicle platform criteria to a programmed threshold, andto return to a refilling station 150 for servicing when the status ofautonomous vehicle platform criteria conforms to the programmedthreshold. For example, the autonomous vehicle platform 100 can beprogrammed with a low threshold of fuel or fertilizer. When theautonomous vehicle platform 100 senses that the actual amount of fuel orfertilizer is at or below the programmed low threshold, the autonomousvehicle platform 100 will autonomously navigate itself to refillingstation 150. Several autonomous vehicle platforms 100 can operate on agiven agricultural field 102, returning periodically to refillingstation 150 to recharge their supply of agricultural chemicals, seeds,fuel, or other supplies.

E. Operation

In operation, a user can deliver one or more autonomous vehicleplatforms 100 to an agricultural field 102, position a refilling station128 proximate the agricultural field 102, and orient the one or moreautonomous vehicle platforms 100 to the field 102 and the refillingstation 128. This can entail the user placing the one or more of theautonomous vehicle platforms 100 in manual mode and driving the one ormore of the autonomous vehicle platforms 100 into a docking position atrefilling station 150. However, this is just one example of how toregister the refilling station 150 location within each autonomousvehicle platform's 100 navigation module 118. The user then activatesthe self-direction program of each autonomous vehicle platform 100. Uponbeing switched into automatic self-direction mode, each autonomousvehicle platform 100 can be filled from the refilling applicator 132connected to refilling tank 130 on refilling station 128. Eachautonomous vehicle platform 100 can navigate to a starting point andbegin navigating up and down rows of planted crops 108, fertilizingplanted crop 104 along the way. In some embodiments, the autonomousvehicle platform 100 can be operated by a service provider who contractswith farmers to conduct in-season management tasks.

In some circumstances, particular areas of the agricultural field 102can be omitted if prior monitoring has revealed that the crop will notbenefit from added fertilizer in that area. In other circumstances,particular areas of the agricultural field 102 can be fertilized for theexpress purpose of monitoring the planted crop 104 response oversubsequent days.

Oftentimes, the outer rows of planted crops 104 are planted around thefull perimeter of the agricultural field 102, with subsequent rows ofplanted crops 108 only running either lengthwise or widthwise. Theperimeter-planted corn that is at the end of the interior rows is oftenreferred to as the “headlands.” A narrow path can be cut through theheadlands if the autonomous vehicle platform 100 must navigate throughthe end of the interior rows. Alternatively, a GPS-guided corn plantercan be programmed to leave several paths through the headlands forfuture autonomous vehicle platform 100 access.

Given the limitations in size of the autonomous vehicle platform 100,particularly in the maximum width W and height H that will allow theautonomous vehicle platform 100 to perform the various in-seasonmanagement tasks between planted rows 108 of an agricultural field 102,the fuel tank, fertilization tank 130, and seed reservoir 146 arerestricted in size. Accordingly, each tank must be sized proportionatelyto the others to ensure that any given tank does not become the limitingfactor in the autonomous vehicle platform 100 completing its operations.To accommodate various fertilization and seeding requirements, thevarious tanks can be modular and removable from the autonomous vehicleplatform 100 to allow for the optimum tank capacity combination.

Among other logistics solutions required for optimal operation, theautonomous vehicle platform 100 can carry a pre-calculated amount offuel and fertilizer needed to fertilize complete sets of rows from theperspective of the refilling station 150. This pre-calculated amount offuel and fertilizer goes hand in hand with appropriately sizing thevarious tanks, as discussed previously. This prevents the autonomousvehicle platform 100 from having to transit more than once over the samepath between rows.

Additionally, the placement of the refilling station 150 can be guidedby a logistics software program. The logistics software program canaccount for the anticipated quantities of fuel, fertilizer, and seed tobe used. These anticipated quantities can be computed using a variety ofinputs, including the field layout, topography, soil condition, andanticipated weather conditions, and other conditions that may increaseor decrease the amount of fuel, fertilizer, and seed to be used. Thegoal of the logistics software is to minimize the time a givenautonomous vehicle platform 100 is traveling to and from the refillingstation 150 to refill its fuel tank, fertilization tank 130, or seedreservoir 146.

In another embodiment, the refilling station 150 can have a retractablehose that can be pulled several rows into the agricultural field 102,beyond the headlands described above. In this embodiment, the refillingapplicator 154 can be mounted on a stand, such as a tripod, to aid inrefilling. In another embodiment, the refilling station 150 can betrailer-drawn. In this embodiment, a pump is required to refill thefertilization tank 130 of the autonomous vehicle platform 100.

Moving one or more autonomous vehicle platforms 100 and refillingstations 150 from field-to-field can be guided by one or more pc- orweb-based software programs that a user can access via smartphone,tablet, interface on base station, or personal computer at the farmheadquarters. Such a program can report the progress made by theautonomous vehicle platform 100 on a particular agricultural field 102,as well as overall statistics for a given time period. Accordingly, theuser can prioritize her/his fields for treatment. With the user's input,the program can then determine the most efficient schedule for refillingthe fuel tank, fertilization tank 130, or seeding reservoir 146, andwhere the refilling stations 150 should be located. Via this program,the user is prompted at the appropriate time to begin the process ofrefilling and/or moving a refilling station 150 such that the autonomousvehicle platforms 100 can operate as continuously as possible. Thelogistics software can also schedule maintenance and transport betweenagricultural fields 102 of the autonomous vehicle platforms 100. Thegoal of the logistics software is to minimize the time each givenautonomous vehicle platform 100 is traveling to and from the refillingstation 150, waiting in queue to be refilled, or is otherwise notperforming in in-season management tasks.

What is claimed is:
 1. An autonomous vehicle platform system for selectively performing an in-season management task in an agricultural field while self-navigating between rows of planted crops, comprising: one or more autonomous vehicle platforms, wherein each autonomous vehicle platform includes a base operably coupled to a plurality of ground engaging wheels, each autonomous vehicle platform having a length, width and height, the width so dimensioned as to be receivable within the space between two rows of planted crops, wherein each autonomous vehicle platform is programmed with a self-direction program to autonomously navigate the autonomous vehicle platform, and to avoid other autonomous vehicle platforms, while selectively performing an in-season management task within an agricultural field.
 2. The autonomous vehicle platform system of claim 1, further comprising one or more refilling station, wherein each autonomous vehicle platform is programmed to compare the status of autonomous vehicle platform criteria to a programmed threshold and to navigate to the refilling station for servicing based on said comparison.
 3. The autonomous vehicle platform system of claim 1, wherein the each autonomous vehicle platform includes a user interface configured to transmit data to a user of the autonomous vehicle platform, and further configured to receive command data from the user of the autonomous vehicle platform from a remote location for selectively overriding the self-direction program.
 4. The autonomous vehicle platform system of claim 1, wherein the in-season management task is the application of fertilizer.
 5. The autonomous vehicle platform system of claim 4, wherein fertilizer is applied substantially between rows of planted crops.
 6. The autonomous vehicle platform system of claim 5, wherein the fertilizer is applied using a spiked drum.
 7. The autonomous vehicle platform system of claim 4, wherein the fertilizer is in a liquid form.
 8. The autonomous vehicle platform system of claim 7, wherein the fertilizer is applied by spraying fertilizer into a cut made in the soil by a coulter.
 9. The autonomous vehicle platform system of claim 4, wherein the fertilizer is applied proximate to the base of planted crops.
 10. The autonomous vehicle platform system of claim 4, wherein the fertilizer is in pellet form.
 11. The autonomous vehicle platform system of claim 10, wherein the pellet is injected into the soil.
 12. A method for fertilizing between rows of planted crops within an agricultural field with one or more autonomous vehicle platforms, comprising: positioning one or more refilling station proximate an agricultural field; delivering one or more autonomous vehicle platforms to the agricultural field, wherein each autonomous vehicle platform is programmed with a self-direction program; orienting the one or more autonomous vehicle platforms to the refilling station; and activating the self-direction program of each autonomous vehicle platform, wherein the self-direction program is programmed to autonomously navigate the autonomous vehicle platform between rows of planted crops, and to avoid other autonomous vehicle platforms, while selectively applying fertilizer within an agricultural field, and to compare the status of autonomous vehicle platform criteria to a programmed threshold and to navigate to the refilling station for servicing based on said comparison.
 13. The method for fertilizing of claim 12, wherein the self-direction program can be selectively overridden remotely through a user interface for each autonomous vehicle platform.
 14. The method for fertilizing of claim 12, wherein the self-direction program directs each autonomous vehicle platform to apply fertilizer substantially between rows of planted crops in an agricultural field.
 15. The method for fertilizing of claim 14, wherein the fertilizer is applied using a spiked drum.
 16. The method for fertilizing of claim 12, wherein liquid fertilizer is sprayed into a cut made in the soil by a coulter.
 17. The method for fertilizing of claim 12, wherein the fertilizer is applied proximate to the base of planted crops.
 18. The method for fertilizing of claim 12, wherein the fertilizer is in pellet form.
 19. The method for fertilizing of claim 12, wherein the pellet is injected into the soil.
 20. An autonomous vehicle platform for selectively applying fertilizer to the soil of an agricultural field while self-navigating between a series of two rows of planted crops, comprising: a vehicle base having a length, width and height, the width so dimensioned as to be insertable through the space between two rows of planted crops, the height so dimensioned as to preclude interference with the canopy of the planted crops; a plurality of wheels; at least one powertrain fixedly coupled to the vehicle base and operably coupled to at least one of the plurality of wheels; a fertilization module; a navigation module configured to receive field orientation information and detect obstacles; a microprocessor in communication with the fertilization module and the navigation module, programmed with a self-direction program to autonomously navigate the autonomous vehicle platform while selectively applying fertilizer based in part on received field orientation information and detected obstacles; and a user interface in communication with the microprocessor, configured to transmit microprocessor data to a user of the autonomous vehicle platform, and further configured to receive command data from the user of the autonomous vehicle platform for selectively overriding the self-direction program. 